Commonly upper and lower spaced pairs of driven fluted rolls are used in conjunction with debarkers at the infeed and outfeed. The flutes on the rolls are arranged and shaped to provide a cradle for the logs and to grip and propel the logs forward responsive to powered rotation of the rolls. This is accomplished by having sets of right and left complementing flutes meeting at the center of each roll such that the ends of each flute are displaced circumferentially of the roll from the inner end and by gradually narrowing the height (width) of the complementing flutes along approximately the inner half of their length so that when viewed in elevation the complementing flutes have a generally "V" configuration. This central portion of the flutes normally provides most of the support and traction for advancing the log and is commonly provided with a serrated configuration to better grip the log. Accordingly, the central flute portion is subject to most of the wear and must be replaced from time to time. However, to accomplish this repair the roll must be removed in order for the worn flutes to be removed. The latter is relatively difficult task because the flutes are welded to the roll.